The utilization of genetically engineered mouse (GEIVI) strains is an integral component of this GTBT P01 program project. The mouse model Core will provide all the necessary expertise, reagents and services for the analysis of exosomal biology with regards to therapeutic applications in GEM models of GBM. The services and reagents provided by this Core will synergize with the individual Projects on the validation and assessment of exosomal-associated molecular biomarkers and the application of cutting edge monitoring technologies for tumor response to therapeutic agents. In addition, the Core will produce and characterize three new GBM GEM strains over the funding period. As such, the Core will support all aspects of the construction of these new transgenic mouse models, including advice, service, technologies and reagents for the optimal design and construction of each specific strain. Using these new strains, the Core will also evaluate and implement new technologies for the detection and monitoring of various exosomal metrics in close relationship with the individual Projects.